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Kenneth Paradiso
Assistant
Professor
Rutgers University
Department of Biological Sciences
Nelson Biological Labs - D418
Busch Campus
Piscataway. NJ 08855-1059
(732) 445-4569
FAX - 5870
paradiso@biology.rutgers.edu |
Pre- and postsynaptic physiology at the calyx of Held
The primary goal of my research is to better understand the process of
synaptic transmission. Typically, electrical recordings of neurons in the
mammalian brain are restricted to postsynaptic neurons and presynaptic
activity is inferred from postsynaptic responses. A notable exception is
the calyx of Held, which permits patch clamp recording of a CNS nerve
terminal to study presynaptic electrical activity. Paired nerve terminal
and somatic recordings allow simultaneous measurements of pre- and
postsynaptic activity. In addition, I use capacitance recordings to
measure changes in membrane area to study the mechanisms of exocytosis and
endocytosis. This preparation allows innovative experiments, and
collaborations across disciplines. Using the calyx, I recently
demonstrated that small currents, physiologically produced in nerve
terminals, travel up the axon a significant distance, ~500 µm, to inhibit
or facilitate action potential generation (Paradiso and Wu, Nature
Neuroscience, 2009). This finding indicates that nerve terminals do not
simply receive action potentials, but can also send electrical signals
back toward the soma to affect action potential generation. The calyx of
Held has been used to study a variety of presynaptic processes such as
presynaptic degeneration, nitric oxide signaling, plasticity, presynaptic
calcium, and analog signaling. My proposed experiments will determine how
currents associated with action potentials affect neurotransmitter release
in the presynaptic terminal. These studies will be done at an early and
later stage of development to determine if synapse maturation alters the
effects of these currents. Future experiments will involve using the calyx
of Held, and other nerve terminals, to study presynaptic neuropathology.
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